Mobile ladders and platforms



July 9, 1957 e. P. EASTON MOBILE LADDERS AND PLATFORMS 2 Shet's-Sheat '1Filed Jan. 12. 1955 INVENTOR. GEORGE P. EASTON ATTOR NEY S United StatesPatent Ofific e 2,798,652 Patented July 9, 1957 MOBILE LADDERS ANDPLATFORMS George P; Easton, Portland, Greg. Application January 12,1955, Serial No. 481,387

Claims. (Cl. 228-4) This invention relates to mobile ladders andplatforms and is particularly adapted to be used for overheadmaintenance in buildings and the like.

The primary object of the invention is to provide a mobile ladder andplatform that can be safely and easily converted from a movable ladderinto a movable ladder and platform.

Another object of the invention is to provide a mechanism within theladder structure that is automatic in operation when converting the samefrom a movable platform to a firm or stationary platform.

Another object of the invention is to provide in a mechanism of the typedescribed, adequate and adjustable guard rails to protect the workmenfrom accidents.

Another object of the invention is to provide dash pot mechanisms forsafely lowering the work tray and guard rail assembly.

Another object of the invention is to provide carrying space within theladder assembly for transporting equipment therewith.

Another object of the invention is to design the ladder and platform sothat the same can be telescoped to a minimum height for passing throughdoor openings and for operating under low ceilings.

Another object of the invention is to provide a work tray which ismovable for elevation as well as a horizontal position in connectionwith guard rails so that the operator can work freely and safely.

Other and further objects and advantages of this invention will becomemore apparent from a consideration of the following specification whenread in conjunction with the annexed drawings, in which:

Figure 1 is a perspective View of an assembled ladder and platform,constructed in accordance with this invention, showing the same readyfor use.

Figure 2 is a fragmentary enlarged detail view of one of the supportingmembers, partially broken away, illustrating the dash pot arrangement inconnection with the lowering of the tray and railing.

Figure 3 is a plan view, taken on line 3-3 of Figure 1, illustrating aplan view of the work tray, partially broken away for convenience ofillustration.

Figure 4 is an enlarged detail sectional view of the railing and trayconstruction, taken on line 4-4 of Figure l.

Figure 5 illustrates how the railing and tray are folded out of workingposition.

Figure 6 is a detail side view of another preferred form of constructionof ladder wherein the overhang platform is eliminated.

Figure 7 is a fragmentary section taken on line 77 of Figure 5.

Figure 8 is a plan view of the base of the ladder and platform, taken online 8-8 of Figure 1, parts broken away forconvenience of illustration.

Figure 9 is. a side view of Figure 1, partially broken away forconvenience of illustration.

Figure 10 is an end sectional view, taken on line 10-10 of Figure 8.

Figure 11 is a fragmentary sectional view, taken on line 11-11 of Figure8.

Referring more specifically to the drawings, this new and improvedladder and platform consists of a box-like base 10, consisting of sidewalls 11 which are laterally bent at right angles to form a top wall 12at their upper ends. The top wall 12 is reversely bent at right anglesto provide side walls 13, and the side walls are bent laterally at rightangles to provide an integrally formed countersunk tray 15. The loweredges of the side walls 11 are bent laterally inwardly to form a bottomwall 16, and again upwardly to form a side wall 17, the bottom of thebase being open. By constructing the base as above described, arelatively light material having a maximum of strength can be used dueto the shaping of the material.

The base 10 is supported upon caster wheels 18 at one end, and upon thewheels 19 on its opposite end. The wheels 19 are journalled within forks20, which are nonrotatable and fixedly secured to the base at 21. Thecaster wheels 18 are journalled within sockets 22 which are fixedlysecured to one end of the arms 23. The other end of the arms 23 arepivotally connected on the brackets 24, the latter being fixedly securedto the bottom wall 16 at 25. The sockets 22 are guided within theU-shaped guides 26 which are fixedly secured to the base 10 at 27 and 28by welding or other means.

Ears or brackets 29, integrally formed with the U-shaped guides, areadapted to support opposite ends of the cross shaft 30 which isjournalled for rotation therein. The cross shaft 30 is provided withearns .31 which extend beyond the ends of the shaft at 32 and areadapted to ride on the upper surface 33 of the arms 23.

A lever 34 is fixedly attached to the cross shaft 30 and has a footpedal 35 on its upper end adapted to be operated manually by anoperator. A dog 36 is fixedly formed on the shaft 30 and is adapted toengage the end 37 of the pawl 38. The pawl 38 is pivotally mounted tothe brackets 39 which are fixedly secured to the underside of the top ofthe base 10.

A treadle 40 is pivotally mounted to the base of the ladder 41 at 42.The forward edge 43 of the treadle has a foot 44 extending downwardly.This foot is adapted to engage the outer end 45 of the pawl 38, as bestillustnated in Figures 7, 8 and 1G. The end 415 and the treadle 40 arenormally held in a raised position by the spring 46. The spring 46 hasone of its ends connected to the pawl at 47 and to the under surface ofthe top of the base at 48. The end 37 of the pawl is adapted to engagethe dog 36 and when so engaged the cams 31 will raise the leg 49 of thebase 10 from the supporting surface by forcing the arms 23 and thecasters 18 downwardly, supporting the weight of one end of the basethereon until the pawl is disengaged from the dog by the action of thetreadle 40, which will be more fully described later on.

The ladder 41 is fixedly mounted to the base 10 by welding or othermeans. The hand rails 5d are fixedly secured to the base and have theirhorizontal runs 51 secured to the top of the ladder 41 by welding, asbest illustrated in Figure 1. Vertical standards 52 are fixedly securedto the base 10 at 52 and to the horizontal runs 51 at 54. This assemblyis further braced by the gussets 55.

A platform 56 is supported at one of its ends on the top of the ladder41 and the standards 52, and is supported at it opposite end by thediagonal braces 57, which are secured to the ladder at 58, to thestandard 52 at 59, and to the platform 56 at 60. Vertical standards 61adjustable for height are telescoped Within the standards 52, and aremaintained at any adjusted position by the set screws 62. Hand rails 63are fixedly secured to the upper 3 .endsof theverticalstandards.61.at,64. ,Ihehand rails/63 are further supported bythe vertical standards 65.

Sleeves 66 are welded to the inner ends of the extenisionnbars-or.angles167 and are, adaptedtoreccive. thetends of the rails 63. Ears 68extend downwardlyzfrom the .sleevesand have the upper; ends of thestandards .65 pivotally connected thereto. The lower. ends. ofthestandards being afiixed to the platform 56 at 69 by bolts and wingnuts. The hand rails 63 terminate in a U-shaped-end370.

.A-work tray 71 is fixedly secured to the upper surfaces of theextensions 67'and may be adjusted away and towards the operator standingon the platform 56. The

lower end of the standards 61 have air sealing cups '72 affixed to theirlower ends, which act as dash potsso that the tray'assembly and railing63, when lowered to the level of the-platform best indicated in Figure5, will not drop suddenly. The sealing cup '72 traps the air within thestandards 52 and the air being gradually released through the bleederholes 73 located at the bottom of the standards 52.

Outwardly extending brackets 74 are located on the "upper ends of thestandards 61 and are adapted to sup port the folding standard 65' whilein folded position. Counterweights 75 are located in the forward end ofthe base and are adapted to counterbalance the weight of the operatorwhile standing on the outer end of the platform 56.

In Figure 6 another preferred form of ladder and platform isillustrated, wherein the overhanging platform56 is eliminated and onlythe guard rail and tray is used. This type of ladder and platform isused where it is not necessary for the operator to be extended beyondthe confines of the platform. It will be noted that the top 14 of theplatform is countersunk within the platform, the object of this is sothat maintenance equipment and supplies can be moved about with theladder and platform in the performing of various operations.

"The operation of this new and improved ladder and platform will now bedescribed. When used as illustrated in Figure l, the standards 61 areraised from the position shown in Figure and locked in adjusted positionby theset screws 62. The folding standards 65 are removed from theirhooks '74 and brought to the position shown in Figure 1 and attached tothe platform 56 by the bolts and wing nuts 69. The tray assembly is thenmoved to the position shown from that shown in Figure 5 by loosening theset screws 66A and sliding the extension members 67 outwardly on therails 63 to the desired location.

Ordinarily the ladder and platform are carried on the wheels 19 andcaster wheels 18, allowing it to be pushed about from place to place,but when finally located it is desirable to instantaneously lock theladder to the supporting surface so that it will not move when theoperator climbs the ladder and stands on the platform 5'6. When heplaces his foot on the treadle 40, the foot 44 of the treadle will pushthe end 45 of the pawl 38 downwardly, referring particularly to Figure10. This will disengage the end 37 of the pawl from the dog 36.

The Weight of the ladder and platform will cause the cams 31 to rotatein the direction of the arrow, permitting the arms 23 to raise to thebroken line position in Figure 9, dropping the legs 49 down on thesupporting surface, thus preventing the ladder and platform from movingwhile the workman is performing his work on the platform 56. The railing63 is always in position while the workman is working on the platform56. This railing can be raised even' higher than is shown in the drawingand a box or other object may be used to set on the platform 56, raisingthe workman still higher in emergency work. In this event the standard65' would have to be exchanged for longer ones.

This ladder and platform is especiallyadapted to be used in rooms havingoverhead lighting to be maintained, although I do not wish to belimitedto any particular use for the device, as it is adapted to many.

.In order toraise the supporting-legs 49 away'from the supportingsurface the operator presses down on the pedal 35 which rotates theshaft 30, cams 31, which in turn raises the platform by forcing the bars23 down, together with the casters 18, thereby raising the legs 49 fromthe supporting surface allowing the ladder and platform to be movedabout. This operation can take place when the operator is on theplatform working by another operator who then can move the ladder andplatform while the workman is on the platform 56. 7

When the railing 63 is lowered to the position shown in Figure 5, theentire unit can be moved through doorways and through restricted places,but after being located in the desired location as described above therailing is brought up into operating position so that the workman isprotected in performing his maintenance work.

Although a certain specific embodiment of the invention has been shownand described, it is obvious that many modifications thereof arepossible. The invention, therefore, is not to be restricted exceptinsofar as is necessitated by the prior art and by the spirit of theappended claims.

What is claimed is:

l. A ladder device comprising a pair of upwardly extending spaced andparallel side members, a plurality of longitudinally spaced risersconnected to and extending between said members, a substantiallyrectangular base, said members having one of their respective adjacentends connected with said base adjacent a side thereof, a pair ofinverted substantially U-shaped members having the'bight portionsthereof secured to said base, said U-shaped members each having a wheelrotatably supported between the sides thereof, a pair of sockets, anelongated arm for each of said sockets, each of said arms having one ofits ends fixedly secured to one of said-sockets, respectively, the otherends of said arms being pivotally mounted on said base, said socketseach being disposed adjacent the other pair of corners of said base, apair of caster wheels mounted for rotation within said sockets, abracket secured to said base adjacent each of said sockets, a shaftrotatably supported in and extending between said brackets, a leverhaving one of its ends fixedly secured to said shaft, the. other end ofsaid lever projecting above said base, a pedal fixedly secured to saidother end of said lever, a cam for each end of said shaft, said cambeing adapted to engage said arms to force said caster wheels downwardlyupon the exertion of force upon said pedal, a pair of elongated legs,said legs being disposed adjacent each of said other corners of saidbase and depending therefrom, means mounted on said base adjacent saidone side thereof for moving said cam away from said arms, a pair ofelongated substantially hollow tubular standards, said tubular standardshaving one of their respective ends fixedly secured toa side of saidbase oppositely disposed with respect to said first side thereof, a pairof upwardly extending hand rails, said hand rails having one of theirrespective adjacent ends secured to said one side of said base'and theother ends thereof being fixedly secured to said standards adjacent theother ends thereof, means fixedly securing the other end of said sidemembers to said other ends of said hand rails, an elongatedsubstantially rectangularplatform having an end thereof fixedly securedto said other ends of said side members, said platform overhanging saidbase, a pair of spaced substantially parallel rectangular braces havingone of their ends fixedly secured to said side members, said braceshaving their respective other ends fixedly secured to the other end ofsaid plat form, a second pair of hollow tubular standards, said secondpair of standards having one of their ends telescoped within said otherends of said first pair of tubular members, means for fixedly securingsaid second pair of standards in selective position relative to saidfirst pair of standards, an elongated substantially U- shaped hand rail,said hand rail having the arms thereof fixedly secured to the other endsof said second pair of standards, a sleeve slidably mounted on each armof said U-shaped hand rail, a tray fixedly secured to said sleeve, meansfor securing said sleeves in adjusted position on said arms, a lugdepending from each of said sleeves, a third pair of standards, meanspivotally connecting one end of each of said last-named standards withsaid lugs, and means releasably securing the other end of saidlast-named standards to said platform.

2. A ladder as defined in claim 1, and a piston mounted on saidtelescoped ends of said second pair of standards.

3. A ladder as defined in claim 2, and means on said other ends of saidsecond pair of standards for supporting said third pair of standards inpivoted position upon release of said other ends of said third standardsfrom said platform.

4. A ladder device comprising a pair of upwardly extending spaced andparallel side members, a plurality of longitudinally spaced risersconnected to and extending between said members, a substantiallyrectangular base, means connecting one of the adjacent ends of saidmembers with said base adjacent a side thereof, said base beingsupported on a pair of wheels fixedly secured adjacent the cornersthereof at the side of said base opposite said first side, a socketmounted in each of the other corners, said sockets each having one endof an arm fixedly secured thereto, means pivotally connecting the otherends of said arms on said base, a cross rod journalled for rotation onsaid base, a cam member secured on each end of said rod, each of saidcam mem bers having contact with one of said arms, respectively, wherebydownward movement of said cams effects a pivotal movement upwardly ofsaid first side of said base about the axis of said first pair ofwheels, means for locking said base in pivoted position, a pair ofdepending legs having the upper ends thereof secured to said base eachadjacent one of said second pair of wheels, the lower ends of said legsbeing elevated above the supporting surface of said wheels when saidbase is in its pivoted position, and means for releasing said lockingmeans to efiect an engagement of the legs with said supporting surface.

5. A portable ladder comprising a base, a pair of wheels secured to theunderside of said base at one end thereof, a pair of legs positionedunder said base at the opposite end thereof, a second pair of wheelspositioned below said base adjacent said legs, said second pair ofwheels and said first pair of wheels being adapted to support said basefor movement on a supporting surface, means mounting said second pair ofwheels in vertically adjustable relation to said base whereby saidWheels can be adjusted to carry said base in one position and to permitsaid legs to carry said base in another position, releasable means forelevating said base with relation to said second pair of legs, saidreleasable means being adapted to maintain said base in elevatedposition until released, a pair of spaced parallel side members securedto the upper side of said base and extending upwardly therefrom, meansextending upwardly from said base supporting the upper ends of said sidemembers, a plurality of spaced parallel steps secured to and extendingbetween said side members, means pivotally mounting the lowermost ofsaid steps to said side members, said pivoted steps being adapted to bemoved downwardly in use, means associated with said pivoted step forreleasing said releasable means whereby said legs are permitted to moveinto contact with the supporting surface restraining said base againstmovement thereon.

References Cited in the file of this patent UNITED STATES PATENTS1,439,388 Willett Dec. 19, 1922 2,035,294 Black Mar. 24, 1936 2,362,170Swaisgood Nov. 7, 1944 2,371,092 Williams Mar. 6, 1945 2,624,590 TiltonJan. 6, 1953 2,701,168 Schemers Feb. 1, 1955

